This invention relates to nanometer scale electromechanical systems. In particular, the present invention relates to nanometer scale electromechanical systems that may be used in various applications, such as heat engines, heat pumps, or propulsion systems.
Electromechanical systems that rely on molecular motion are known. For example, U.S. Pat. No. 4,152,537 (the xe2x80x9c""537 patentxe2x80x9d), describes an electricity generator that produces electrical energy from the random movement of molecules in a gas, and the uneven distribution of thermal energy in different molecules of the gas, which is at an overall uniform temperature.
Other such systems are described in, for example, U.S. Pat. Nos. 3,365,653; 3,495,101, 2,979,551; 3,609,593; 3,252,013 and 3,508,089. These systems produce electricity or devices driven by electricity, such as an oscillator, based on molecular motion and thermal energy.
One problem common to all of these systems is the low level of output power when compared to the amount of power required to operate the systems. For example, such systems often require a certain amount of energy to maintain the systems at a constant overall temperature. While the ""537 patent attempted to address some of the known deficiencies in such systems, the electricity generator described therein also suffers from similar deficiencies. For example, the ""537 patent attempts to heat the thermocouple junction between two dissimilar materials by simply being in contact with a gas-molecule having an above-average speed. In addition, the ""537 patent utilizes an array of electrical rectifiers (see, e.g., rectifier bridge 40 in FIGS. 2 and 4) that may have difficulty in operating properly due to the infinitesimally small voltages produced at the molecular scale.
Moreover, as the use of electronic devices continues to flourish, there is an ever increasing need to provide more efficient and/or quieter ways to cool the components that are typically the heart of such devices. For example, most personal computers include one or more fans that are required to maintain the temperature of the microprocessor within a certain operational range. These fans are often noisy, and often result in large quantities of dirty air being pulled through the computer from the air intakes.
Accordingly, it is an object of the present invention to provide nanometer scale electromechanical systems that efficiently convert molecular-level energy into another form that can be used at a macroscopic scale.
Another object of the present invention is to provide nanometer scale electromechanical systems that efficiently convert molecular-level heat energy into useful mechanical and/or electrical energy.
A still further object of the present invention is to provide nanometer scale electromechanical systems that utilize molecular-level energy to create a pressure differential on a surface of an object to propel the object in a controllable direction.
An even further object of the present invention is to provide nanometer scale electromechanical systems that utilize molecular-level energy to heat or cool an external substance.
The nanometer scale electromechanical systems of the present invention efficiently convert molecular-level energy from one form into another form by reducing the velocity of the molecules within the working substance. These systems may include, for example, a heat engine that converts molecular-level heat energy into useful mechanical or electrical energy. Such systems may also include a heat pump that utilizes molecular-level energy to either heat or cool a substance. For example, a system of the present invention may be mounted to a microprocessor as the primary cooling device, so that little or no fans would be necessary. In addition, these systems may also include propulsion systems in which molecular-level energy is utilized to create a pressure differential on the surface of an object, thereby providing the ability to propel that object in a controllable direction.
Nanometer scale electromechanical systems constructed in accordance with the present invention may include a large number of nanometer-sized objects, such as paddles, impact masses, and/or tubes, that are placed in a liquid or gas. These objects may be sized on the order of several nanometers per side, and may have a thickness on the order of about one or two nanometers. One side of the paddle is connected to a flexible, spring-like, attachment, that couples the paddles to a common base. Also attached to each paddle is some form of generator device, such as a piezoelectric, electromotive force or electrostatic generator, that converts random molecular motion into electrical, electromagnetic or thermal energy.
The nanometer-sized paddles, in conjunction with an associated generator, reduce the speed of individual molecules which results in a reduction of thermal energy within the working fluid. The generated electrical energy may be converted back to thermal energy at a higher temperature than the working fluid and used to establish a temperature differential that is capable of performing useful work. Essentially, the paddles are configured to be immersed in a working substance. The paddles move in a random manner within the working substance due to variations in the thermal motion of the molecules of the working substance. This movement necessarily results from collisions between the molecules of the working substance and the paddles which are large enough to cause the paddles to oscillate. The kinetic energy from this oscillation may then be converted into electrical, electromagnetic or thermal energy by various methods, as described above.
Nanometer scale electromechanical systems constructed in accordance with the present invention also provide components that efficiently collect and sum the outputs of the numerous paddles so that a useful electrical output is produced. For example, one embodiment of the present invention includes the use of an array of resistive elements, one for each paddle, that are in contact with one side of the thermocouple. The other side of the thermocouple is placed in thermal contact with something else that is at an ambient temperature (such as a gas or liquid). Each of the thermocouples produces an output (i.e., a DC current and voltage) that can be summed through a simple series connection to produce an output, depending on the number of paddles and configuration, on the order of several milliwatts.
In one particular embodiment, a nanometer scale electromechanical system constructed in accordance with the present invention may include an array of nanotubes, such as tubes made of carbon, which are coupled between two plates of a capacitor. One of the tubes is physically connected to one plate of the capacitor, while the other end is free to move. The entire assembly is immersed in a fluid (i.e., a liquid or a gas). A voltage is applied to the capacitor (across the plates), which creates an electric field (xe2x80x9cExe2x80x9d) that keeps the length of the tubes perpendicular to the surface of the capacitor plate. The xe2x80x9cfreexe2x80x9d ends of the tubes, which are immersed in a working substance, move erratically due to collisions between the molecules of the working substance and the tubes, causing some of the tubes collide into each other. Kinetic energy of the colliding tubes, as well as other energy, may be converted for one or more useful purposes, as previously described.
In another embodiment of the present invention, numerous nanotubes are connected at each end to an electrically and thermally conductive rail. Each of the tubes is installed such that there is slack, or bend, in the tube. The slack permits the tubes to vibrate in response to random pressure variations from surrounding fluid (gas or liquid). In this case, an external magnetic field (xe2x80x9c{overscore (B)}xe2x80x9d) is applied to the entire assembly which is perpendicular to the tubes and rails. Heat generated in the tubes, from the induced current, flows down the tubes to the thermally conductive rails, which are attached to a thermally conductive plate.
Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description of the preferred embodiments.